Many applications of integrated circuits are embodied within a highly integrated system such as a system-on-chip (SoC). In some of these applications, the SoCs are required to work from low supply voltages and to consume relatively low amounts of power. In such applications, the SoCs incorporate functions (such as a wakeup detect function) that are enabled during a sleep mode of the SoC. In such sleep modes, various battery or system monitoring applications are “on,” and accordingly are designed to work from low voltages to save power. Almost all of these SoCs have a bandgap reference circuit to provide a constant voltage reference. Such bandgap reference circuits are typically required to have capability to generate accurate reference voltages even at low supply voltages.